In the recent tendency of the art, a long guide trough is constructed by stamping monolithic refractory material in one block instead of being constructed by brickworks, and transported and settled in the place where it is to be used. The method is also used for repairing the troughs, in which, when the inner surfaces of the troughs are worn by running molten products, whole of the trough is replaced with a new one instead of repairing by lining worn surfaces.
Such troughs are so heavy--some of them weigh about 1 ton or more--that the outside of the refractory body is reinforced by a supporting member, such as plates or frame works, which are usually provided with hook plates projecting upwards and having hook engaging holes for hanging the trough body.
As the hook plates are projecting upwards from the trough body, hook plates are exposed to the heat radiation and splashes of the hot running molten products while in use, and this may weaken the hook plates and cause damages. Further, piling up of the troughs in the storage is hindered by such projections.